In addition to developing his kitchen skills, we've been offering the boy greater responsibilities around the house as well.
His laundry responsibilities, in addition to putting his own dirty clothes into the hamper, had previously included bringing the dry clothes from the dryer in the garage into our house, as well as basic washcloth folding. Bringing in the dry clothes has now been passed on to his younger brother, while the boys' new responsibilities include putting away the clothes for the three kids (I had initially asked him to put away the clothes for him and his brother, but he insisted he could do his baby sister's clothes as well) and sorting the laundry. Next up, advanced folding!
Other current household responsibilities include assisting in unloading the dishwasher, vacuuming the living room, setting the table for the kids, clearing away his dishes after a meal, cleaning up his toys before bedtime, keeping his room tidy, and general assistance when requested. He also enjoys window washing, but that remains a skill-in-progress.
It has been interesting to observe the link between meaningful work and personal initiative/responsibility. The more (age-appropriate and reasonable) meaningful work we give him, the more he demonstrates awareness of household needs and a willingness to take them on himself. He has, for example, taken on the responsibility of undoing both of his little sibling's carseats when we arrive at our destination, in addition to other self-initiated responsibilities.
Social Studies: Responsibility